Parkes observations for project P991 semester 2019APRS_05

Finding radio pulsars orbiting near Sgr A* is a major goal of pulsar surveys with existing telescopes and future telescopes such as the Square Kilometer Array (SKA). The discovery of such pulsars will allow us to measure relativistic effects through timing of pulsars in tight orbits around Sgr A*, to characterise the distribution of dark matter near Sgr A*, to study the stellar population in the GC region and to probe the scattering region around Sgr A*. Although several surveys of the GC region have done, the Ultra-Wideband Low (UWL) receiver provides us a much wider frequency coverage with great sensitivity and therefore it is an excellent chance to revisit the GC region. At around 4GHz, a survey with UWL will achieve a sensitivity significantly higher than previous Parkes and Green Bank surveys, especially for pulsars with short spin periods and high dispersion measures.

利用现有望远镜以及平方公里阵列（Square Kilometer Array, SKA）等未来望远镜开展的脉冲星巡天项目，核心目标之一便是在人马座A*（Sgr A*）附近搜寻绕转的射电脉冲星。发现此类脉冲星，将使我们能够通过对人马座A*近邻紧密轨道脉冲星的计时观测，测量相对论效应；还可用于刻画人马座A*附近暗物质的分布、研究银河中心（Galactic Center, GC）区域的恒星种群，并探究人马座A*周围的散射区域。尽管此前已针对银河中心区域开展过多项巡天观测，但超宽带低频段（Ultra-Wideband Low, UWL）接收机拥有更宽的频率覆盖范围与优异的灵敏度，因此为我们重新探测银河中心区域提供了绝佳契机。在约4GHz频段下，采用超宽带低频段接收机开展的巡天观测，其灵敏度将显著优于此前帕克斯（Parkes）与绿岸（Green Bank）望远镜开展的巡天项目，尤其针对自旋周期较短、色散量较高的脉冲星。